Most perovskite-type ceramic materials with a general formula of ABO3−δ are mixed electronic and oxygen ion conductors at high temperature and are known to be suitable materials for making dense oxygen semi-permeable membranes. These membranes hold promising applications in air separation and partial oxidation of hydrocarbons to hydrogen and carbon monoxide. Despite tremendous interest and efforts from both academic institutes and industrial companies, the applications of dense ceramic membranes made of perovskite-type oxides are still facing many technical challenges. These include fabrication of pin-hole free dense membranes, developing high temperature sealing and joining techniques to integrate a particular membrane with other parts of the reactor system, and controlling the chemical and mechanical stability of the membrane during the harsh operating conditions. In addition, there are issues related to safety and economy of ceramic membrane reactor applications.
It has been discovered by the present inventors that perovskite-type oxides in non-membrane form exhibit both good oxygen storage capability and/or catalytic properties for high-temperature air separation, total combustion, partial oxidation and steam reforming reactions. Historically, perovskite-type oxides in non-membrane form for a high-temperature air separation process as well as in a cyclic auto-thermal reforming (CAR) process have been disclosed. In the CAR process, air and natural gas/steam mixture are contacted alternately with perovskite-type oxides. The present inventors have further discovered that perovskite-type oxides, when supported by porous support, show higher reactivity and faster oxygen exchange rate than the unsupported ones.